Compressor valve



May 31, 1932. P. ANDERssoN COMPRESSOR VALVE Original Filed May lO, 1926'/5 25 39 O C /7 f /a 40 22 --kv 38 /6 u ,9 A 4 /vw/e/vvtoa/ I mn A?, 220 \F `Patented Mayl 31, 1932 PELLE annnnsson' oF rnrILWauKEE,-Wisconsin, Assrenon .fro- ALLis-cHALMnns MANUEACTURING COMPANY, OFMILWAUKEE, WISCONSIN, -CORPORATION OF.

` DELAWARE ooivrrmisson VALVE Y Org'inalapplireatimi led May 10, 1926,ASerial No. 107,907. Divided and. this application led January 18,V

, 1929. Serial The present inventiony relates generally to new anduseful improvements in the cone structionV of valves,l and relatesmorespecifi cally to improvements in valve structures especiallyk adaptedfor use in connection with compressor unloadingV devices.

' An object ofthe invention is to provide an improved valve structurewhich issimple in construction and efficient in operation.

U Another objectoff the'inventionis to vprovide anew and useful diskvalve which is especial-` ly applicable for unloading purposes in airand' gas compressors; These andV other objects Vof theinventionwillappear from the i following description.

The present application is a division of ap- Vplication Ser. No.l07,907, 4led May 10, 1926, patented March 19,k 1929', No. 1,706,37 3.

A clear conception of several embodiments 'A26 of the novel features andof the operation of devices einbodyingthe invention, may be had byreferring to the drawings accompanying and forming a partfof thisspecification in which like reference characters designate 'T275 thesame or similar parts in the various views.

Fig. l is a somewhat' diagrammatic and part sectional side elevationofacompressor cylinder, the section being taken adjacent toy one of theinlet valves. v

Fig. 2 is an enlarged sectional view of oneV of the compressor ,inletyvalves showing the unloading mechanism associated therewith.

Fig. 3 is an enlarged sectionalview of one of the compressor inletvalves having a modified form of unloading mechanism associatedtherewith. f

The compressor to .which lthe'-ini'fentionrv 'oscillatable duringoperation of the comhas been specifically applied herein,v is of `theconstant speedltypeand comprises a cylinder 2 having therein a usualform of reciprocable piston, and also' having end heads 3, 4f Withinwhich are located inleta-nd exhaust valves communicating with-the air:supply v'and discharge conduits 36, 37 respectively. The compressorpiston may-be' reciprocated in any :convenient manner, asr byv ankelectric motor, and the pressure Yofthe compressed air deliveredthrough.the discharge conduits 37 variesV according to the kdemand fori-air iat the source of utilization." v

rlhe improved inlet valve structure shown urged toward an annular seat24' formedon". the seat element 20,'by means of one or more springs i9`which react against a valve stop l?. The valve stop 17 kis rigidlysecured to' the seat element 2O by means of a clamping bolt 21, and hasarec'ess 'formed to receive the valve y18 when in open position, so thatthe discharge edge of the valve 18 is `compietelysurrounded by anannularlip 23v when the valveis'fully open.

The improved unloading' device shown in Fig. 2, comprises ya bridgepiece or member 16 movably supported from the seat element y by means of'parallel links 15, 25, `and is disposed between the valve 18 and apositioning Vcam 14. The links l5, 25 are mounted to swing about upperfixed pivots and have theirlower ends pivotally associated with lowerpivots secured to the lbridge memberl 16, thereby causing'the Contactsurface of the member 16 to always assume parallel positions. vvTheybridge member 16 carries la roller which is. held in engagement withone of the surfaces 38, 39, ofthe cam 14 by means `of a spring 22 whichreacts against f the seat element 20. The cam la is supported upon a camshaft 11 and has an arcuate unloading surface 38, a second arcuatebridge releasing surface 39 of shorter radius than that of the surface38, and an intermediate surface 40 connecting thek surfaces 38, 39, allof the surfaces 38, 39, 40 being adaptedto engage the roller 35 atcertain. times. The

cam shaft 11 is angularly `adjustable and presser, by means of a rockerarm 13k and a connection 9, in a manner Yto be later eX- plained. Y'

The modified unloading device shown in Fig. 3, comprises a bridge pieceor member 26 movably suspended from *the cylinder head 4 and from anextension on the seat element 20,'by Vmeans of an arm 27 formed integralwith the member 26.` The arm 27 'is pivotally supported'at its upperendv and lcarries aroller `35 .at its lower extremity,4`

which cooperates with the surfaces 38, 39, 40, 'Liv of the adjacent cam14. The remainder of the unloading device of Fig. 3 is substantiallysimilar to that of Fig. 2, both in strueture and mode of operation, butthe contact surface of the member 26 does not move to parallelpositions.

The actuating mechanism for the unloading devices, comprises a regulator5 mounted laterally adjacent to the cylinder 2 and consisting of anauxiliary cylinder having therein a vertically movable plunger 29. Apipe 28 provides a connection from the discharge conduit 37 or otherpressure source, to the oil chamber within the regulator easing, andthis oil chamber communicates with the plunger chamber past a needlevalve 41. The plunger rod 30 is adaptedv to transmit motion to levers 31whichV are in turn adapted to adjust the T-lever 7 about itssupportingpivot 33, through a'connection 32. The supporting pivot 33 of theT-lever 7 is associated with the lower swinging end of the oscillatorylever 6 the upper end of which is supported by a fixed pivot 42. Thelever 6 is swingable back and forth during normal 'operation of thecompressor, by means of a connection 34, and the upper and lower arms ofthe T-lever 7 are joined to the rocker arms 12, 13 by means ofconnections 8, 9 respectively. Aspreviously explained, the rocker arms12, 13 are secured to the cam shafts 10, 11 carrying the unloading cams14.

During normal operation of the com. presser, the piston is beingreciprocated to alternately draw air into and discharge air from theopposite ends of the cylinder 2 through the inlet and discharge conduits36,' 37. The connection 34 is being reciprocated simultaneously with thereciprocation of the piston, thus producing oscillation of the lever 6about the pivot 42 and causing the T- lever 7 to rock withy the lever 6.The rockingmotion of the T-lever 7 is transmitted through theconnections 8, 9 and the arms 12, 13 to the cam shafts 10, 11 thusproducing periodic rocking movement of the cams 14. When the cam 14 isin the position shown in Fig. 2 with the cam surface 38 engaging theroller/ of the adjacent bridge member, throughout the rocking movement,the bridge member holds the inlet valve 18 in open position throughoutthe compression stroke and the compressor isfully unloaded. When tbe cam14 is in the position shown in Fig.

. With the cam surface 39 in engagement with ythe roller 35 of thebridge member, throughout the rocking movement, the bridge member doesnot engage the inlet valve 18 andr this valve functions normally toadmit air to the cylinderfon the suction stroke and to prevent escape ofair past the valve on the return stroke.

By proper adjustment of the position of the cams 14, unloading mayobviously be effected during any desired portion oit' theV compressionstroke. Such adjustment of the cams 14 may be automatically accom lishedin accordance with variations in t e discharge pressure or of any othervariable operating characteristic, by means of the regulator 5. As thepressure admitted through the pipe 28 increases, the plunger 29 and rod30,move upwardly thereby causing the cam surfaces 38 to become effectiveand increasing the duration of the unloading action, and vice versa.

With the construction shown in Figs. 1 and 2, the contact surface of thebridge member 16 is always advanced to parallel positions by virtue ofthe parallel links 15, and always has surface engagement with the valve18 when the unloader is effective. While the construction shown in Fig.3 does not produce such parallel positioning of the contact surface, therelatively long supporting arm 27 allows but slight angular displacementof this surface resulting in slight tilting of the valve 18.

The lip 23 surrounding the valve 18 prevents the air which returns-tothe inlet'conduit 36 during unloading, from returning the valve to itsseat 24 thereby'producing highly eiicient unloading. The lip 23k hasspecial utility when applied to sheet metal valves 18 used in connectionwith compressor unloading devices, as it' prevents the yair which isreturned to the inlet conduit, from forcing the peripheral edges of thevalver toward its seat 24, and thereby undesirably restricting the freedelivery of air from within the cylinder. When unloading is takingplace, the annular plate valve 18 is positioned entirely' within theannular recess of the Valve stop'17, and the air being delivered fromthe cylinder does not come in cont-act with the side of the valve whichfaces `the cylinder, excepting when the valve 18 is in closed position.The annular sheet metal or plate valves 18 are of simple constructionand have proven highly efficient in operation.

It should be understood that it is not desired to limit the inventionclaimed to the exact details of construction shown and'described, forobvious modifications may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. An unloading device fory compressors comprising in combination, avalve seat element adapted to be inserted in a compressor,a valvetherein actuated durin operation of the compressor, a stop for limitingthe opening movement of said valve secured to said seat element, saidstop being provided with an annular lip for closely surrounding aperiphery of said valve when in full open position and means for holdingsaid valve in full open position during unloading of the compresser.

2. In a one-way inlet valve structure for compressors, a valve seatelement adapted to be inserted in a compressor, an annular sheet metalvalve, -a stop for limiting the openingmovement, of said valve securedto said lseat element, said stop having anannular lip coml pletelysurrounding the periphery of said valve When fully open, means forconstantly yurging said valve away from said stop,and

vmeans for holding said valve Within said lip during unloading of thecompressor.k c

3. In a one-Way inlet valve structure for compressors, a valveseatelement adapted to be inserted in a compressor, an annular sheetmetal valve, spring means for constantly urg-k ing said valve towardclosed position, a stop for limiting the opening movement .of said valvesecured to said seat element,said stop having an annular projectionvsurrounding the periphery of said valve When fully open, and means forholding said valve Within said projection during unloading of the,compressor.

4.' In a one-Way inlet valve 'structure for compressors, a valve seatelement adapted to Vloe inserted ina compressor, an'annular sheet metalvalve, a stop for limiting the'opening movement-of said valve secured tosaid seat element, said stop havingl a recess forming a lip entirelysurrounding the periphery of said valve When open, and a bridge memberfor holding said valve `Within saidk stop rec cess during unloading ofthe compressor.

5. In a one-Way inlet valvestructure'for compressors, a` valve seatelement adapted to he inserted in a compressor, a sheet metal valve, astop for limiting the opening movement ofsaid valve secured to said seatelement, said stop having a` recess therein forming a projectionsurrounding the periphery of said valve When open, and means for holdingsaid valve .Within said recess, to permit free escape of air from thecompressor around said projection during unloading of the compressor.

6. In a one-Way inlet valve structure for compressors, a valvefseatelement adapted to v he inserted in a compressor, an annular platevalve,-a stop for said valve secured to said seat element, said stophaving an annular recess adjacent to said valve, and means for holdingsaid valve entirely Within said recess during unloading of thecompressor.

7. In a one-Way inlet valve structure for compressors, a valve seatelement ladapted toy be inserted in a compressor, an annulary platevalve, a stop for said valve secured to said seat ele-ment, for limitingthe' opening move,-Y

inent of said valve, said stop having a recess adjacent to said valve,and'means Jfor holding said valve entirely Within said recess when at amaximum distance fromr said seat element. l l

In testimony whereof, the signature of the Y inventor is a-ixed hereto.

- PELLE ANnERssoN. Y

